Knowledge of the pericardium (pericardial sac) dates back to the time of Galen (129-200 A.D.) the Greek physician and anatomist who created the term "pericardium." The pericardium (pericardial sac) is a conical membranous sac in which the heart and the commencement of the great vessels are contained. Gray's Anatomy (1977 ed.) pp. 457-460. The pericardium is fluid-filled and functions to prevent dilation of the chambers of the heart, lubricates the surfaces of the heart, and maintains the heart in a fixed geometric position. It also provides a barrier to the spread of infection from adjacent structures in the chest cavity and prevents surrounding tissue(s) from adhering to the heart. The space between the pericardium and the heart, known as the pericardial space, is normally small in volume and includes fluid therein. It has been reported that when fluid is injected into the pericardial space it accumulates in the atrioventricular and interventricular grooves, but not over the ventricular surfaces. See, Shabetai R, "Pericardial and Cardiac Pressure," in Circulation, 77:1 (1988).
Pericardiocentesis, or puncture of the pericardium has been performed for: 1) diagnosis of pericardial disease(s) by study of the pericardial fluid; 2) withdrawal of pericardial fluid for the treatment of acute cardiac tamponade; and 3) infusion of therapeutic agents.
Methods for accessing the pericardial space are known. For example, U.S. Pat. No. 5,071,428 (Chin et al.) discloses a method and apparatus for accessing the pericardial space for the insertion of implantable defibrillation leads. This method requires gripping the pericardium with a forceps device and cutting the pericardium with a scalpel (pericardiotomy) under direct vision through a subxiphoid surgical incision.
Uchida Y., et al., "Angiogenic Therapy of acute Myocardial Infarction by Intrapericardial Injection of Basic Fibroblast Growth Factor and Heparin Sulfate," in Circulation AHA Abstracts (1994), reported a method for the intrapericardial injection of angiogenic agents. While not described in detail, this method generally involved the percutaneous transcatheter bolus injection of drugs into the pericardial cavity via the right atrium.
U.S. Pat. No. 4,991,578 also discloses apparatuses and methods for accessing the pericardial space for placement of defibrillation electrodes. One apparatus disclosed uses suction to "pull" the pericardium against a perforating needle housed in an outer catheter, thus impaling the pericardium on the needle. Another apparatus disclosed includes a catheter through which suction is applied to draw the pericardium into the lumen of the catheter. Once drawn in, a wire suture is applied to stabilize the pericardium to the catheter, a piercing needle inserted through the pericardium, and a guidewire passed through the needle into the pericardial space. This patent also discloses accessing the pericardium from the outside (i.e., through the parietal pericardial layer) with a needle after separating the outer layer from the epicardial layer by distending the pericardial space with a fluid passed into the space through a perforation made through the atrial wall.
U.S. Pat. No. 5,269,326 discloses passing a catheter into the right atrium and puncturing through the right auricle tangential to and between the epicardium and pericardium. U.S. Pat. No. 5,336,252 discloses a tri-lumen apparatus for accessing the pericardial space to implant electrical leads in the pericardial space.
The present invention provides new devices for accessing the pericardial space as well as kits and methods for performing diagnostic and medical procedures in the pericardial space.